The present invention relates to a method of manufacturing a printed circuit board (PCB) and a PCB manufactured by the same, and more particularly, to a method of manufacturing a PCB in which an oxide layer for protecting a circuit pattern formed on a substrate is formed using an anodizing process, and a PCB manufactured by the method.
In recent years, as electronic appliances are scaled down and their functions are more complex, multi-chip packages (MCPs) or stacked chip scale packages in which integrated circuit (IC) chips are stacked are being widely employed. An IC package substrate used for the MCP or the stacked chip scale package must have a predetermined thickness or less so that the MCP or the stacked chip scale package can be applied to small-sized electronic appliances with complex functions.
A conventional method of manufacturing a printed circuit board (PCB) necessarily includes a process of coating solder resist in order to prevent oxidation of an exposed circuit pattern (or interconnection pattern) on an outer surface of a substrate and electrically insulate circuit patterns from one another. The solder resist is a kind of paint and is obtained by corroding copper foil coated on the substrate. Basically, the solder resist is a bare wire that is not coated with an insulating material.
FIG. 1 is a block diagram of a conventional gold electroplating process using a lead wire, and FIGS. 2A through 2C are diagrams illustrating a conventional method of manufacturing a PCB using a gold electroplating process.
Referring to FIGS. 1, and 2A through 2C, in step S10, an interconnection pattern 2 and a lead wire pattern 3 are formed on a surface of a substrate 1, and a solder resist 4 formed of an insulating material is coated on the entire surface of the substrate 1.
Thereafter, in step S20, a dry process, an exposure process, and a developing process are performed, thereby forming a window 5 in which a chip (not shown) is mounted on a predetermined portion of the substrate 1 so that a bonding finger 2a is exposed on the substrate 1.
Subsequently, in step S30, a power source 6 is connected to the lead wire pattern 3 and the bonding finger 2a is electroplated with gold 2a′ in order to improve bonding efficiency.
However, since it is necessary to form a gold-plating lead wire in order to electroplate the bonding finger 2a with gold, manufacturing the conventional PCB is complicated and costly.
Also, the conventional solder resist has a high moisture absorption rate and a high coefficient of thermal expansion, so that the conventional PCB cannot ensure high reliability.
Furthermore, when the substrate 1 has a very small thickness, a stiffened plate must be further adhered to the substrate 1, and thus moving or handling the PCB at an interval between process steps during a package assembly process is difficult.